The present invention generally relates to antenna communication systems and in particular to a remote, tilt antenna system.
Conventional communication systems for Cellular and Personal Communication Systems (PCSs) use interconnected communications networks to allow network users to communicate with one another. PCS networks include a number of Mobile Switching Centers (MSCs) that connect network users to Private Switched Telephone Networks (PSTNs) and other MSCs. The MSCs are connected to and control a number of base stations. The base stations are located in the cells of the network in order to provide network coverage in the area that is local to the base station. The base stations are equipped with antennas that allow communication between the base station and mobile users or PCS users within the cell where the base station is located. The base stations communicate with the MSCs to allow PCS users to communicate with other PCS users and PSTN users.
Optimization of the coverage provided by the base stations for the PCS users is very challenging due to the large number of parameters necessary for successful network operation. The positioning of the base stations and their associated antennas is important to overcoming such problems as channel interference caused by overcrowding from adjacent base stations, in addition to other factors, such as the topology surrounding the base station. One method used to reduce interference with other nearby base stations is the use of down-tilt antennas. Down-tilt antennas help reduce the problem of cell site overlap by adjusting the vertical angle of radiation transmitted by the antenna with respect to the surrounding area serviced by the antenna. By positioning the antennas with a downward tilt, the area to which the radiation is dispersed by the antenna can be decreased thereby reducing interference with other base stations. However, the antennas must be carefully positioned in order to provide the necessary coverage while avoiding interference with other cells or microcells within the network and adjacent competing networks. Unfortunately, conditions at the base stations that may affect coverage can change over time requiring adjustment of the antenna position or down-tilt. As a result, the positioning of the antennas must be periodically adjusted.
For example, seasonal variations in weather and temperature may affect the radiation patterns associated with the antenna. Changing topology, due to the addition of new base stations, buildings, etc., can also affect interference, radiation patterns, and coverage associated with the base stations. As a result, it becomes necessary to adjust the positioning or tilt of the antennas.
First generation solutions used a mechanical assembly to adjust antenna down-tilt. However, this solution requires that a technician travel to and climb the tower and physically adjust each antenna every time it was necessary to adjust or provide a new antenna down-tilt. This is especially costly and time consuming when setting up a new system since several adjustments are normally required in order to provide the necessary system optimization.
Second generation solutions provide antennas with electrical down-tilt. While this solution has made it easier for the technician to position the antennas, second generation systems still require a technician to travel to the site and climb the tower by a technician, each time an antenna needs adjusting. As a result, even with electrical positioning of the antennas the problem of the required system down time for adjustments and costs associated with having to send a technician to the site remains.
It is therefore an object of the invention to improve coverage provided by antennas in radio communication networks.
It is another object of the invention to provide an automated antenna system that can be automatically adjusted from a remote location.
It is a further object of the present invention to provide an antenna system that may be dynamically adjusted in real-time to respond to changing conditions.
It is a yet a further object of the present invention to provide an antenna system that can verify antenna position and test antenna elements to ensure proper operation and detect any faults associated with antenna position and operation.
It is also an object to reduce costs associated with optimizing and maintaining a network of communication antennas.
According to an exemplary embodiment of the present invention the foregoing and other objects are accomplished through implementation of a remote down-tilt antenna system. According to the invention, an antenna control system is connected to an antenna in order to control the position of the antenna. The system includes a motor connected to the antenna for adjusting the position or tilt angle of the antenna. A driver is provided for operating the motor. A sensor is also provided to detect the position of the antenna. In addition, an antenna controller is connected with an antenna memory, the driver, and the sensor for reading the detected position of the antenna and for controlling the driver to adjust the antenna""s position. A main controller is connected to the antenna controller for sending commands to and reading data from the antenna controller, for example, the antenna""s position. In this manner the main controller can interface with any number of antennas at a base station and control the position of each antenna.
According to an exemplary embodiment of the control system, a user interface is also provided for entering commands to and reading data from the main controller. The interface can be provided at the base station, tower, or at a remote location via, for example, a modem. According to one embodiment of the invention the user interface can be a laptop computer. A user or technician can then enter commands and monitor the positions of the antennas from a remote location allowing for real time adjustment of antenna position.